docs: def init_app(app, *storages):
      '''
      Initialize Storages configuration
      Register blueprint if necessary.
  
      :param app: The `~flask.Flask` instance to get the configuration from.
      :param storages: A  `Storage` instance list to register and configure.
      '''
  
      # Set default configuration
      app.config.setdefault('FS_SERVE', app.config.get('DEBUG', False))
      app.config.setdefault('FS_ROOT', join(app.instance_path, 'fs'))
      app.config.setdefault('FS_PREFIX', None)
      app.config.setdefault('FS_URL', None)
      app.config.setdefault('FS_BACKEND', DEFAULT_BACKEND)
      app.config.setdefault('FS_IMAGES_OPTIMIZE', False)
  
      state = app.extensions['fs'] = app.extensions.get('fs', {})
      for storage in storages:
          storage.configure(app)
          state[storage.name] = storage
  
      from .views import bp
      app.register_blueprint(bp, url_prefix=app.config['FS_PREFIX'])